Osteoma is the most common benign tumor of the paranasal sinuses. They remain asymptomatic until the tumor reaches a certain size. Although the etiology of the osteomas is controversial, embryologic, traumatic, and infective theories have been proposed. Osteomas may be discovered at any age but are usually found during the fourth and fifth decades, and there is a male preponderance. In this retrospective study, we analyzed 25 patients with paranasal sinus osteomas who were treated surgically between 2005 and 2011. Age and sex of the patient, size and location of the tumor, clinical presentation, type of surgical approach, duration of follow-up, outcome, and any intraoperative or postoperative complications were obtained from the medical records of the patients. Diagnosis of osteoma was based on computed tomography findings and confirmed histopathologically in all cases. There were 9 men (36%) and 16 women (64%) with a mean age of 38.7 years. Tumor localization was divided as follows: ethmoid sinus in 14 patients (56%), frontal sinus in 9 patients (36%), and maxillary sinus in 2 patients (8%). Mean tumor size was 2.04 cm, ranging from 0.5 to 6.5 cm. External approach was used in 9 cases and endonasal endoscopic surgery was performed in 19 cases. Combination of endoscopic surgery and external surgery was performed in 3 cases. After at least 6 months of follow-up, all patients were symptom-free except 2 patients who underwent revision surgery. These 2 patients were also asymptomatic following revision surgery. Although there is an increasing trend to endoscopic surgery, external approach is recommended in large frontal osteomas and ethmoid osteomas with lateral extension and in case of intracranial or intraorbital involvement.